DESCRIPTION (Applicant's Description): Dr. Schofield has a solid background in service pathology and some experience in routine and molecular cytogenetics. Her primary interest is in pediatric solid tumors and she would like to obtain additional experience and training in molecular genetics in order to pursue this interest and establish an independent academic career. This Mentored Clinical Scientist Development Award will enable her to limit her current clinical/service-related commitments, and spend 80 percent of her time gaining additional experience with the technical and theoretical aspects of molecular genetics. Her ultimate goal is to establish an independent research career investigating the molecular genetics of pediatric solid tumors. The research proposal centers around an attempt to define the rhabdoid tumor, a poorly understood and controversial childhood neoplasm which is generally associated with a dismal prognosis. Preliminary studies performed by Dr. Schofield have shown that approximately 80 percent of renal rhabdoid tumors have loss of genetic material on chromosome 22q. Under the sponsorship and guidance of Dr. Jeffrey Sklar, molecular genetic techniques, including construction of a bacterial artificial chromosome contig and screening of a cDNA library, will be used to identify a proposed tumor suppressor gene on chromosome 22 which is involved in the genesis of these tumors. Once identified, the gene will be characterized and other rhabdoid tumors will be screened for deletions or mutations.